Citrix Application Enumeration and Session Launch

Accessing a Citrix Session is combined by two methods. Application Enumeration and Session Launch. Here are the brief about the steps which take place during the process/

Part: 1
User Authentication and Resource Enumeration

1. A user initiates a connection to the NetScaler Gateway URL and provides logon credentials.
   
2. The credentials are validated against Active Directory.
   
3. NetScaler Gateway forwards the user credentials to StoreFront.
   

4a. When StoreFront is in the same domain as the controller, StoreFront validates the user credentials against Active Directory and forwards to the Delivery Controller.

4b. When StoreFront is not in the same domain as the Delivery Controller, credentials are forwarded to the Delivery Controller for validation against Active Directory.

1. The XenDesktop Delivery Controller retrieves a list of available resources by querying the SQL Database.
   
2. The list of available resources is sent to StoreFront, which populates the user’s Citrix Receiver, Windows Start Menu or browser
   

Part 2: Session Launch

1. When the user selects a resource from 1 Receiver, the request is sent to StoreFront through NetScaler Gateway.
   
2. StoreFront forwards the resource request to the Delivery Controller.
   
3. The Delivery Controller queries the SQL Database to determine an appropriate host to fulfill the request.
   

1. The Delivery controller sends the host and connection information to StoreFront (443).
   
2. StoreFront requests and receives a one-time- use ticket via the Secure Ticket Authority.
   
3. StoreFront generates a launch file, including the ticket information, which is sent to the user through NetScaler Gateway.
   
4. Citrix Receiver uses the launch file and makes a connection to the NetScaler Gateway (443).
   
5. NetScaler Gateway validates the ticket with the STA (80 or 443)
   
6. NetScaler Gateway initiates a connection to 9 the resource (1494 or 2598) on the user’s behalf.